议论文一般应该具备论点(viewpoint)、论据(fact，evidence)和论证(substantiation)三要素。论点是作者阐述和说明的立场和观点，即表明自己对有争议的问题所持的态度。论点的基本要求是：观点鲜明，提纲挈领，有实际意义。写议论文时，一般总是在开始时先将所议论的问题和自己的立场和基本论点阐述清楚。往往文章的标题可以指明所讨论的问题，但作者的立场和基本论点则要体现在主题句中，如果缺少明确的观点，没有观点鲜明的主题句，文章就在很大程度上失去了力度。为了明确观点，往往在写主题句的时候，措辞直截了当，语气肯定，避免模棱两可、语气含混。如knowledge is power； Modest makes progress； Smoking not only pollutes the enviroment， but also is harmful to peoples" health。 论据是用来证明论点的依据，是说明论点的理由和材料，是议论的基础，解决“用什么证明”的问题。所选论据必须真实；所引史实、名言、科学知识和数据必须可靠，准确无误；论据与论点之间必须构成因果关系。也就是说，在选择某些论据来证明某个论点时，一定要使论据材料和被证明的观点相一致；否则，论据缺少说服力。同时要选择有新意的论据，即使是同一个事例，只要注意挖掘，也可以从不同的角度证明不同的观点。论证就是用论据来证明论点的过程和方法，它解决“怎样证明”的问题。论证的过程，就是分析问题、解决问题的过程，也就是逻辑推理的过程。议论文的论证方法总的是提出问题，分析问题，解决问题。具体来说有归纳法(induction：通过个别事物，归纳其共性(共同点)，得出结论)、演绎法（deduction：从分析典型，即分析事物总的特征入手，推断到同类事物也有相同的特点或结果）、因果分析法（casual analysis： 对事物的原因结果进行分析后，得出结论，支持论点）、对照法（comparison and contrast： 对所有事实、主题的各方面进行对照，然后加以分析，得出结论），驳论法（refutation：先列出错误的观点，然后加以逐条批驳，最后阐明自己的观点）和例证法（illustration：通过举例说明，论证观点）等。
2.议论文的写作技巧
（1）怎样确立明确的论点。
一篇好的议论文都必须有明确的论点，表明作者的立场。如何写好明确的论点是写好议论文的第一步，那么怎样才能确立明确的观点。首先，分析文章的题目或所给的背景材料，有些文章的标题就可以指明所议论的问题，如话题①：Unity Is Strength.题目观点明确，表达恰当。话题②：Schools place too much emphasis on testing。题目明显是对当前学校的考试制度的批判，对学校过分重视考试提出质疑。观点很清楚，作者是想通过列举事实来证明学校过度重视考试会带来弊端。第二，如果给你的是一段背景材料，需要作者自己确立题目和观点，这是应注意客观事实(如John is a middle school student，这是一个客观事实，不存在争辩的理由)，模棱两可的句子(如Teachers should give students homework，but not too much，句中观点模糊，too much 一词表明作者自己没有明确的观点)、过于武断的句子（如college students should never be absent from class，never一词有强加和不明事理的倾向）及个人喜好（如Ba Jin is my favorite author）等情况的句子不宜做主题句。
（2）议论文的写作模式。
议论文的结构一般分为引句（introduction）、正文(body)和结论句（conclusion）三部分。一般在引句部分提出论点，即文章的主题；在正文部分摆出有利的事实，对论点进行严密论证；最后根据前面的论证得出结论。
（3）议论文的开头模式一般如下。
①用一组统计数据或事实(statistics/facts)作引言。Short introduction. A quotation or aphorism bearing on the general subject may be used. 如话题：Life Can Be Happy and Meaningful. 开头段：Not long ago， a poll was conducted among student in a middle school. They were asked to make a choice between these two sentences-“No one can be happy”， and “One can be happy.” Shockingly enough， about 20 percent of the students agreed to the first statement.
②表明主题的重要性（importance of topic）：e.g. The Constitution guarantees it. The colonists were protected by it and modern day Americans insist on it. The right to bear arms means Americans should be able to purchase guns for their protection and for their sport.
③列举对比情况（comparison or contrast situation）：先列举相互对立的观点，并提出作者的观点。如话题： Three Gorges Project Is Beneficial. 开头段：The Three Gorges lie in the middle reaches of the Yangtze River. After years of investigation and research， many scientists and engineers have suggested that to control the floods brought by the Yangtze River to its lower reaches， a large dam should be built there. But many other scientists and engineers disagree. Thus a heated debate has begun as to whether the project is benefical. I am in favor of the project and believe that it will have more advantages than disadvantages.
④问题形式（questions）： e.g. Is your husband using his computers to cheat you？ Are you kids fantasizing about sex on the internet？ Do you know where your kids and spouse are？ If they are in front of the computer， you might have reason to worry. There are several reasons why the computer is not “man"s best friend.”
(4) 议论文结尾写法模式。
①呼吁作出改变(make a plea for a change)。
e.g. The parents， the schools and the government must make a combined effort to educate young people about the dangers of drug abuse. Moreover， the whole society must change its attitude toward such over the counter preparation as sleeping pills， diet pills and tranquilizers. The careless use of these durgs creates an atmosphere that invites the use of illegal narcotics. When we realize our full responsibility in dealing with this problem， drug addiction may begin to disappear as a national menace.
②重申观点，得出结论（draw a conclusion）。
如话题：Work for Money or Enjoyment？ 结尾部分：Although money plays an important part in good life， enjoyment is the basic factor of good life. My point of view is that working in a good enviroment and for enjoyment is a more intelligent goal.
（5）议论文整篇写作模式。
Part I： Introduction： Sentences 1： to give relative background information on the subject. Sentence 2： to attract and hold reader"s attention (e.g debate focus of the topic).
Sentence 3： to put forward the main idea of the article (viewpoint).
Part II： Body： sentences： state and clarify different aspects of the topic idea.
Sentences 1： give more facts and examples to support your idea.
Sentences 2： to give some comments on the opposite idea.
Part III： Conclusion： using sentences restate the thesis in a different way.
Ending sentences： draw a conclusion.
可以看出，议论文遵循这样的论述方法：简短引言→作者论点的明确陈述→提供论据→议论结果→得出作者的结论。
(6）范文分析。
兹以下范文说明议论文的写法。
Topic 1.
How Important Is Money？
No one would argue， I think， that money is unimportant. There are certain things that human beings need--food， shelter， perhaps medical care--and those things cost money. But if one has enough money to live on， to pay for the basic essentials of life， is it important to have a lot more money than that？ Will your life improve in proportion to the amount of money that you have？
Well， there is no denying that money can buy a lot. Maybe you do not need much money to pay for simple shelter， but how about you want a nice， big apartment in a nice neighborhood， or if you want to buy a house？ That fact is that people do get on each other"s nerves if they are crowded together in a small space， and that a married couple or members of a family are likely to get along better if they are not constantly tripping over each other and asking each other not to be so noisyif each can find a little privacy from time to time. A big apartment or a house will allow them this privacy.